With the growth of the networks and the Internet, Internet Protocol (IP) telephony is becoming increasingly popular. Often referred to as Voice over IP (VoIP), it can be used to establish communication between two end points.
In order to establish the communication, the two endpoints exchange messages in order to establish a dialog that describes the characteristics of the communication. The dialog may establish the type of media to be exchanged, for example video and/or audio as well as the protocol used to transfer the communication.
When two endpoints attempt to modify an existing dialog at approximately the same time, a race condition exists. The condition is often referred to as a glare condition, and can be resolved using a back-off time when the two endpoints establish the call between each other directly.
When an intermediary is used to establish the call between two endpoints, it may be difficult to resolve the glare condition. Various attempts of addressing this glare condition have been considered; however these have included modifying the Session Initiation Protocol (SIP) used to control VoIP calls. Therefore there is a need for an improved method and apparatus for addressing glare conditions in SIP.